Tam Yiu-chung, a Hong Kong member of the Standing Committee of the National People's Congress, arrives at a coronavirus testing center at Hong Kong Convention and Exhibition Center on Sept 2, 2020. (PARKER ZHENG / CHINA DAILY)

HONG KONG - Initial results from Hong Kong’s universal testing have identified six infections, in the first indication the experiment will uncover hidden cases.

The new asymptomatic infections emerged after 128,000 people were sampled in the first few days of a campaign to offer everyone in the city a free test. About 884,000 residents had registered for it as of Thursday evening.

The Asian financial hub aims to use the testing drive to detect more hidden chains of transmissions as it tries to avoid future flare-ups after largely bringing its worst COVID-19 outbreak under control

Four of the six cases uncovered by the testing are discharged patients from hospitals, while two are new infections, health officials said Thursday.

READ MORE: HK sees 8 new infections, mass testing finds 6 positive cases

The Asian financial hub aims to use the testing drive to detect more hidden chains of transmissions as it tries to avoid future flare-ups after largely bringing its worst COVID-19 outbreak under control. Local infections in the city have fallen from a peak of 145 at the end of July to only seven cases on Thursday, separate from the testing drive, with four of them having an unknown origin.

But the goal to bring a greater sense of security to Hong Kong may be undermined by the low turnout. So far slightly over 10 percent of Hong Kong’s more than 7 million residents have registered for the testing drive. That leaves open the possibility of more cases spreading undetected, underlining the difficulties cities around the globe face in implementing solutions to contain the spread of Covid-19 in the absence of an effective vaccine.

“We urge more people to participate in the mass testing to end the hidden chains of transmissions quickly,” Director of Health Constance Chan said in a briefing Thursday.

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Hong Kong’s campaign, which kicked off on Sept 1, is the largest global attempt to test an entire city on a voluntary basis. The testing drive is currently slated for one week, while it could be extended to as long as two weeks depending on demand.

As Hong Kong’s virus wave tapers off, the city has been gradually easing social-distancing measures. It announced earlier this week the reopening of schools in phases. The government is also poised to allow gyms and massage parlors to reopen from Friday.